A US woman who shot and killed her husband and two adult children before taking her own life is thought to have committed the shocking crime as a result of being ostracised from the religion she was raised in.

A federal judge sentenced a former Arkansas judge Wednesday to five years in prison — a stiffer punishment than prosecutors recommended — after he admitted giving young male defendants lighter sentences in return for personal benefits that included sexual favours.

Every time I tell a mate I’m doing a story on cryptocurrency, they invariably ask me the same two questions: should they invest their own hard-earned money, and which cryptocurrency will get them a Lamborghini/yacht/island quickest?

In a 60 Minutes online exclusive, reporter Liz Hayes quizzed Australian Prime Minister Malcolm Turnbull on his relationship with the unpredictable Twitter aficionado and US president Donald Trump ahead of their meeting at the White House Friday.

NSW diver takes 'cuddling' selfie with friendly shark

It might have a face only a mother could love – but that hasn’t stopped an Aussie diver from becoming fast friends with this Port Jackson shark.

Rick's Dive School proprietor Rick Anderson said he first befriended the unnamed female shark seven years ago, when it was still just a six-inch-long pup, The Dodo reports.

"I approached her carefully so as not to spook her, then began to gently pat her. Once she got used to me, I would cradle her in my hand and talk soothingly to her through my regulator,” Mr Anderson said.

Mr Anderson said he continued to lavish attention on the pup during the first year, and that when he returned over the next few years, the migratory shark appeared to recognise him, approaching “for a pat and a cuddle”.

(Rick Anderson)

“She soon got used to me — to the point where she will swim up to me when I'm going past, and tap me on the legs until I hold my arms out for her to lay on for a cuddle,” Mr Anderson said.

Mr Anderson has since celebrated the unlikely friendship in a series of photos to his business’s Facebook page, remarking that it has proven a constant source of surprise for other divers.

He insists that he does not feed the shark or others he happens to “play with”, but simply treats them “like dogs”.